The ever-increasing demand for smaller sized mobile devices, such as cell phones, digital cameras, etc. has correspondingly triggered a growing need for smaller sized photography modules comprising elements such as an optical imaging lens, a module housing unit, and an image sensor, etc., contained therein. Size reductions may be contributed from various aspects of the mobile devices, which includes not only the charge coupled device (CCD) and the complementary metal-oxide semiconductor (CMOS), but also the optical imaging lens mounted therein. When reducing the size of the optical imaging lens, however, achieving good optical characteristics becomes a challenging problem.
U.S. Pat. No. 7,502,181, U.S. Pat. No. 7,826,151, and U.S. Pat. No. 8,422,145 all disclosed an optical imaging lens constructed with an optical imaging lens having five lens elements. Each of these patents has an aperture stop positioned in front of the first lens element, that leads the half field of view of the optical imaging lens is 32-33 degrees, which is difficult to meet the requirement of consumers. Besides, the system lengths of the optical imaging lenses of these patents are between 6.5 mm and 8.0 mm, which are difficult to meet the requirement of slimmer mobile devices.
How to effectively enlarge the half field of view of the optical imaging lens and shorten the length of the optical imaging lens is one of the most important topics in the industry to pursue the trend of smaller and smaller mobile devices. Therefore, there is a need to develop optical imaging lens with a shorter length, while also having good optical characters.